Have you ever tried to do the brainteaser below, where you have to connect the dots to make the outline of a house in one continuous stroke without going back over your lines? Or perhaps you've ...

Simon focuses on two challenging problems: Tarsi's Conjecture and Stanley's Tree Isomorphism Conjecture. Tarsi's Conjecture, a type of graph coloring problem, asks whether a special class of graphs ...

Graph colouring, the assignment of colours to the vertices of a graph so that no two adjacent vertices share the same colour, represents a canonical NP-hard combinatorial optimisation problem with ...

In 1852 mathematician Francis Guthrie asked a seemingly simple question that triggered endless dispute, left a trail of overturned publications in its wake and culminated in a resolution that has ...